Without　prior　knowledge　of　medium　parameters,　a　method　is　proposed　to　detect　and　locate　a　target　in　layered　media.　Experiments　were　carried　out　for　liquid/liquid　and　solid/liquid　layered　media,　and　the　location　of　a　target　in　them　was　obtained　using　three　methods　combined,　i.e.,　the　least-square　method,　the　method　of　finding　minimum　dispersal　degree　of　target　distribution,　and　the　snapshot　time　reversal　and　reverse　time　migration　mixed　method.　The　medium　parameters,　i.e.,　the　acoustic　velocities　of　upper　and　lower　media　as　well　as　the　thickness　of　the　upper　medium,　were　inversed　simultaneously.　The　results　show　that　the　position　of　target　is　consistent　with　its　actual　position.　Thus,　the　detection　and　location　of　a　target　in　layered　media　are　achieved　without　prior　knowledge　of　medium　parameters,　and　it　overcomes　the　difficulty　that　the　common　time　reversal　method　only　detects　the　target,　but　cannot　locate　it.